Dust collector



June 29, 1937. c. a M 'KEowN I 8 0 DUST commewon Filed m 51, 1935 2 Shasta- Sheet 1 Arrow/v93,

June 29, 1937. C. G. M KEOWN 1 5 6 DUST COLLECTOR Filed May 31, 1935 2 Sheets-Sheet 2 Fig. 2.

Array/v53 cylinder part.

Patented June 29, 1937 UNITED STATES nns'r COLLECTOR PATENT OFFICE shire County, England Application May 31, 1935, Serial No. 24,436

In Great Britain February 1, 1935 6 Claims. (01. 183-83) This invention relates to centrifugal dust collectors. The circular cyclone collectors at present in use generally have an efliciency in the order of from 70 to 80%, andthe main object of i direction in order to increase the precipitation of dust.

In the preferred form of the invention the forward speed of the airin that part of the collector which it first enters is increased as it travels through its first circuit in the collector, this result being brought about by constructing the air passage of diminishing cross-section. The increase in the forward speed of the air leads to an increase in the centrifugal force that acts on the particles of dust suspended in'the air and thus helps to force the dust against the. wall of the collector. Further increase in the efliciency is also obtained by causingthe air to move in a path of continuously increasing pitch as it passes downwards through a conical portion of the cyclone in continuing its further circular motion after its first circuit. This leads to an increase in downward speed and preferably is brought about by making a part'of the collector in the form of a truncated cone, the wall of which varies in inclination, being least at the point first encountered by the air and gradually increasing, this conical part being placed immediately beneath a cylindrical part through which the air first flows.

Preferably the air leaves the collector through a cylinder or thimble which projects downwardly into the cylindrical part through which the air first flows on entering the collector and which is set off centre relatively to this cylindrical part in two directions at rightangles to one another in such a way as to reduce gradually the distance between the walls of the cylindrical part and the cylinder or thimble in the direction of flow of the air. The outlet cylinder or thimble may advantageously be made concentric with the lower edge of the conical part referred to above, while the upper edge of thatconical part may be concentric with. the cylindrical part. The outlet cylinder or thimble may project downwards from a volute outlet chamber arranged above the In order that the invention may be clearly understood and readily carried into eifect, one dust collector constructed in accordance therewith will now be described by way of example with reference to the accompanying drawings in which v Figure 1 shows a longitudinal section through the middle of the collector, and

Figures 2 and 3 are cross-sections on the lines II--II and III--III respectivelyof Figure 1.

The collector comprises a cylindrical part I which the dust laden air enters tangentially through an opening 2. The air is ultimately taken out of the collector through an outlet cylinder or thimble 3 in the usual way, but instead of this thimble being made concentric with the cylindrical part I it is set oif centre in two directions at right angles to one another, as is shown particularly in Figure 3, so that the distance between the walls of the cylindrical part I and the thimble 3 is gradually reduced in the direction of flow of the dust-laden air, and thus the forward speed of the air is increased as the air travels in its first circuit around the collector.

When the air has made one complete circuit it enters'a part 4 in the form of a truncated cone.

I The upper edge of this conical part 4 is concenupward current of air to flow inside the downward current, as will be apparent from Figure 1,

where the flowing air is indicated in dotted lines.

A conical part 6 is provided to catch the deposited dust.

The clean air passes through the thimble 3 to a volute outlet chamber I leading to an outlet pipe 8. The cross-sectional area of this outlet pipe 8 is the same as that of the inlet pipe 2.

It is found that the eiiiciency of the collector described and illustrated is about 98%, that is to say about 98% of the total dust carried .by the air through the inlet pipe 2 is removed through the outlet cone 6. This high efiiciency is obtained without any increase in the resistance across the collector.

The collector may be used either under pressure, that is to say by forcing the dust-laden air through the inlet at a pressure above atmospheric pressure, or under suction, that is to say by drawing the clean air out through the outlet 8. In the latter casethe interior of the collector in the collector, the conical part having its top,

edge coincident with the lower edge of the cylindrical part, and having its lower edge eccentrically disposed with relation to the lower edge of the cylindrical part, whereby to cause the air in moving downwardly through it to move in a path, the pitch of which increases continuously.

2. In a centrifugal dust collector, a cylindrical part placed to receive the air on first entering the collector, a conical part placed immediately below said cylindrical part, the cylindrical part being bottomless and the upper edge of the conical part being coincident with the lower edge of the cylindrical part, and an outlet cylinder projecting downward into said cylindrical part and disposed eccentrically in relation to said cylindrical part, said outlet cylinder being spaced from the wall of the cylindrical part to leave a passage that gradually decreases in width in the direction of flow between the walls of the cylindrical part and said outlet cylinder.

3. In a centrifugal dust collector, a cylindrical part placed to receive the air on first entering the collector, and a truncated conical part placed immediately beneath said cylindrical part, the

wall, of said conical part varying in inclination, being least at the wall surface slightly beyond the point at which the air enters the collector and gradually increasing, whereby to increase the downward speed of the air as it circulates through said conical part.

4. In a centrifugal dust collector, a cylindrical part placed to receive the air on first entering the collector, an outlet cylinder projecting into said cylindrical part, and a truncated conical part placed immediately beneath said cylindrical part and having its upper edge' concentric with said cylindrical part and its lower edge eccentric with said cylindrical part but concentric with said outlet cylinder.

5. In a centrifugal dust collector, the combination claimed in claim 4 and a second cylindrical part immediately below the conical part said second cylindrical part being larger in diameter than said outlet cylinder.

6. In a centrifugal dust collector, a bottomless cylindrical part placed to receive the air on first entering the collector, a volute outlet chamber placed above said cylindrical part, an outlet cylinder communicating with and projecting downwards from said volute chamber into. said cylindrical part and placed eccentrically therein to leave between the said cylindrical part and said outlet cylinder an air passage that gradually decreases in width in the direction of flow of the air, and a conical part placed immediately below said cylindrical part and having its top coincident with the bottom edge of the cylindrical part.

' CHARLES GEORGE McKEOWN. 

